Japan's lower house chief admitted Thursday to having had some connection with the Unification Church, amid growing calls for him to explain his suspicious ties with the controversial religious group.

Hiroyuki Hosoda, the speaker of the House of Representatives, said in a statement that he delivered speeches twice at ceremonies and took part in two other gatherings between 2018 and 2019, all of which were hosted by the church or affiliated groups.

Hiroyuki Hosoda. (Kyodo)

The veteran ruling Liberal Democratic Party lawmaker also said he was once interviewed for a publication linked to the organization, now formally known as the Family Federation for World Peace and Unification.

The revelation could deal a fresh blow to the administration of Prime Minister Fumio Kishida, who heads the LDP. Opposition parties are set to grill Kishida over the issue during an extraordinary parliamentary session starting Monday.

Hosoda, an LDP heavyweight who became speaker last November, also confirmed a Unification Church-linked group based in his constituency in Shimane Prefecture, western Japan, had expressed its intention to support him in past election campaigns.

Members of the group were ordinary citizens and were not involved in any illegal activity.

Kazuo Shii, head of the opposition Japanese Communist Party, criticized Hosoda and urged him to explain his ties with the group in the Diet, rather than just releasing a statement.

"If he cannot do that, he should immediately step down" as lower house speaker, Shii told reporters.

Hosoda's announcement came amid mounting concern that the religious group, established by a staunch anti-communist in South Korea in 1954, may have sought to exert political influence by deepening ties with ruling party lawmakers.

The organization, often labeled a cult, has come under scrutiny since former Prime Minister Shinzo Abe was fatally shot during an election campaign speech in July.

Abe's attacker has been quoted by investigative sources as saying he harbored a grudge as his mother's substantial donations to the Unification Church had ruined his family's finances and Abe was targeted due to alleged links to the group.

In 2021, Abe appeared in a video message aired at an event held by an organization affiliated with the church.

The LDP has pledged to sever relations with the Unification Church and the results of an internal investigation, released earlier this month, showed around half of the ruling party's lawmakers had some connection with the organization.

Although Hosoda was suspected of having ties with the Unification Church, the LDP excluded the chiefs of both chambers of the Diet from the probe, claiming they were effectively separate from the party due to their parliamentary roles.

Meanwhile, another LDP lawmaker exempted from the investigation, Hidehisa Otsuji, the president of the House of Councillors, said in a separate statement that he had no relationship with the Unification Church.

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